SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '494a7586f2d7f28d6798ac88c93db20a19756a97fb3f5e722a0cc633e8519984' 
  AND token = 'VhJKxKqA4L5ZOD9qfPzYOpyvYmkb+WQmkWKHLTA5CAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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