SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '046da227286921e690039639a8de66de6420c6896038910d672329de7ddc7437' 
  AND token = 'NhrgYXpI9Iomzq7zJ0s1tPUTbFeTSuL+OJi6vmwub2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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