Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0621d1e78a76ee14965d1d0d04bdf3584eb70f61b3fa479ca1035b96e92721bd' 
  AND token = 'rPGmCKBEoN1IXlYzSejxYTvPG1RM3Pdzv6H66+1opJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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