SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efe4b1a28952b9f1194f1fde0dad4d7dca278fa4d1b3a25093f5b1501a9a5f6e' 
  AND token = 'i6CgHQ4QGRqVA2+wMgO+O+0EmAyKnw66OBSRxG5gzl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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