SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3227495412723c64db83261ff75ca200fb8c8d3ea2929818097314ab943a0193' 
  AND token = 'UQ6Pd0SdT6tz2FLlAYY0oncl1583ASKyiwqhmyBEQrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}