SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20722bb82d350734b00881fc04185688b260b8269c5148e53ad61a79843e153a' 
  AND token = 'eBu4VFvoFhKmwAw3yxPuWz/YDxl5t9K8QtCQYs8+7AQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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