SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd26be2ed50e04f38b2fa9f02d76f8096999b9c866d88fae8b31b606b92741cea' 
  AND token = 'QlpQ6RmDSLkJheNCDksh2doaVek4Zr3ySW7Rj3KemH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}