SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93c81474ec07ebc29f248cdf01d7e7077b029adc1ec41c97e416de70b7de84ea' 
  AND token = 'N6s8wxrMhSXXXAqQu9eWZyWjsYFwaNI94mAoXsV/nYg=' 
  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"
    }
  }
}