SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94f03e208d354ab314f55d6195aacf69e1635722e9c1f5132e0ea7768a678ce6' 
  AND token = 'orHvNO28KdrpNlSLeZzDgr57WOnJORAtOeZHJAxmMeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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