SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43609d496414f2134db425b73d3da249984e5eb600763800da554445d13a88bf' 
  AND token = '2zesUcuVaDGb8H6/HjXdIku65ZkCOAzZaXtgS2Cbl54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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