SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c1fc865ac4101064310d648691d984ccdcf6221d9f3809554ebca98abd95920' 
  AND token = 'd6sUAUZXVy+qmE7k3ArF8flF36jmCgBsmMbyqN3cWAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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