SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90e5b649df500543cc1dfe0b5a0a5b9df1db1304c34296cc116eac1474ec9999' 
  AND token = 'YQRfH9WA2QWOtLtVaDDjMvscS46+pLGZtmgyO3LlqXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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