SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0472a9b8c68cf3760913d5f95e7c9dd504f6f709941b8c828fb073639d462db3' 
  AND token = 'uL63DOplMzPDwpUglNwyrZ/zbQEuP6862LAxChiaKOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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