SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e7024885e4a36eb66b47801be42cf90058b66a3966c783dad8032b17b3bfdda' 
  AND token = 'b84KYAoA4A/kknWSMg6KtINAIjFmx7LPfxdNmKzlA1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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