SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '352e6d9c93e0fe5d1a654a27fd69b8a6bc0a14ec0c22f2fa368bbe722d095356' 
  AND token = 'yjN6CLSCi2iv+GKwvUiQnB4c79dBJku/xm8gTA1yufU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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