SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e25db5dd7861d79240adef6a84c9e00ed177754586850ece101bec62b3f40f4d' 
  AND token = 'QBYnZNgmVd8LhG2KGy32AOwWjdrSM5x9ENhLCgAJ+C8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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