SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c038d3c2430359105047d9425420a53ec36562f0e315f40122fc4d29bcf7b491' 
  AND token = 'Gujn1JEkQW1FFjSeizdNcBLBfW5O7wLAPdOKpY16cws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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