SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c947f05f3c46d9c4a25ff356fbc5d79b945f094b89ffe8eceae3f176e5a6efaf' 
  AND token = 'R0fytLKH2rXFU34hNw9i0Q0XJ8VVecI57v29Ai4tj1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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