SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8de45c76dd9e369f5d741a56ef556812f6eb8582c14e5181ad10a9632cf0e3a3' 
  AND token = 'dyvT6sP8Iv5LwVBEZ0H2KmobBlLyihoECGah7HVRiJk=' 
  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"
    }
  }
}