SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc5e9d0a34a9c5ec2b8cd57a6f20bf4c6a34d36abbcf2297e34443314ac8bb66' 
  AND token = 'GzOTFJA52Fq75oYEeL0zO2mR3hMAY+uBvCHuVAvCQlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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