SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5fa493c4d36c0c33550d6e25ad6ab2e1ad12ceba698cf51b8c0293e597267b7' 
  AND token = 'oNW4xVQ6fwgqZ6gwDmQCLWXCbrPum1QvN0Zpjm3qTAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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