SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb240cf5db69317bc5441e8a38bb79b80d5ea2eba1dbdf7099c95c4a3213d3d6' 
  AND token = 'QsqcBRLh3rSIYrOdKDQz7TDKH8ZCN8bfl7velgwm3C8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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