SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27e005e0879b6c0e39cde7c36cf155a015463fd0d135935519e04baa8375ed69' 
  AND token = 'qxfVsEIFj2ZzWfBIyKerioTW6zxKHqpZbASCkMHbXUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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