SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b7b78ee528ed1cc4d16be5de53fe64660d78ed9be9a91f6e06e3f1ee62641a3' 
  AND token = 'y6WSQKTjZgb2Zp+hWyO3e+ipGaNG+7YAjrDmJlKqy5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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