SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f39461f1b8db8472278aa87e48bc910fbdc49a300e55d1d535f0cd85a327ef0' 
  AND token = 'ABqFNiU45Ad9bcxKETA57cjeFJGas/CFGEWMGHMK0WI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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