SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5395f5622ac59cdded0b582b4feb67f182fc071a14d85c174c319d56cc291212' 
  AND token = 'W++1xzo0bY8qCOYSZ3ljFm6QGqGk70//nPE/AppVrqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}