SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5ff3cfdf868e1ef0995c96df5b1eb3b17a109315ca0c885ae5d7b76592053a6' 
  AND token = 'lFRgwM+nB/X7LPq6SwsVprgz1hrX3CN8tqG66IPVVz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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