SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ee4fccaf04f18a72ef56093c4b57ec789f05563e5b3127ea71f723c1e7c5f1d' 
  AND token = '99QyyT+IudJ2ZuHxMBu0oHk0duo315a8BZng7DTketg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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