SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '342f8bbb32e26a8f1822957458c4b35da9288694cbc82672f9504164744c0b8f' 
  AND token = 'qyfi7/LAsRcu1I6j9HpVeApQZqLJaPTV5P8OvXKqYbc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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