SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '362605aec3bcb6bd0c3025305614e822da78439adf7375ad5d52e4b1a7ef3760' 
  AND token = 'yuZAbaxjJmq2ayt1RknWfW1tQeW1XFaVBbd1TDY/4Ew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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