SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18ec1728ae1346e711517b8a03eaa85345a7195d61ecc88e79a590789ec7c992' 
  AND token = 'WgqsPevPJxJuNzo+3kk/H8cCGR7KT2X0hPG9h+fWdj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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