SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44578286bf0c84dfed6f26e1550eb3c781d0166fdc91bf419b50b68ce57f3ff3' 
  AND token = 'JGXnMmhaeF4yVQncgLQOvSfw46EuVo6w/uoCtbYV6JA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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