SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7727036fd92e202762139bc9cd1ed59d42ea5b1f61b4d446ba2fd1a8095794bf' 
  AND token = 'VGi8d1zToT5RAUIEKaOOUCYWAZY5ITu99ZUeCkO+V1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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