SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66483b3a284bde79289b14cb26ea1458a7995c9d343453beda6837ebfbf44d88' 
  AND token = 'qVL6yKmrtAPNAKuTKYX7vkhxJAiMu4ysD4F20e82uMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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