SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b9ad367aed5b8473a9715dff07bf7c2aba6c8780cfa771addb5c5e2692b3356' 
  AND token = 'gZdUw43sJpS6Ej39cV/Q2bStTTb21IVcdrqF20DrLdU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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