SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2948e98482c72d176663088f4d293d4fbf4d89218a4e43120ee9750a2a1cffe1' 
  AND token = 'GA8oLfcj82mY+DeQKvzKlGVk+BbCxWFtUipZydGBvbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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