SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec7042f0b305966066b88b3925b32b239fd0d473ca3db87f117a55fa365dcdff' 
  AND token = 'cByHiscp+QWitLcUkfQetzvpnFHV2c9pUEzo25ZJ+hw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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