SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7f5bd0b72e721aa4d895a161722e3f664660c9224818026f9c783a262aedc7f' 
  AND token = '7UVhOtajrv3EVjBHpFLgVRdPaDPjFFJhq95PRKsrrLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}