SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87233a2db1690ba65abc9dfe74dedef9b7dc68bfb3efa51712a883e6f5a6558e' 
  AND token = 'ARnPlaIciKFtvaSALEpJJhev0Akk/6dm0+DuvJra2S0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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