SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae5ac88ee9ff7ad88cd754204b250b4a59ceaf644333d9366c51c35d5189ed3c' 
  AND token = 'uUk462Qi3j8y2zD2MBQM0ReSWYQLIkDQQBuWC3YJPBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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