SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86a4ccbd3fb90eb36bbc2925eeced71ecbcae805f06aefbab7154564c69425ff' 
  AND token = 'TaORXEV7Pyp/qzU3jvaZtBQ7pHWHmqhSNYtgUueY8Cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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