SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f04136a7285f479a049c4203a1a0b2b03855fa40d3ffafa2b1ae7b9d057a7240' 
  AND token = 'D8lYVsTgkKl+NbDzrL46LBFBMJomF2JLmLlA7yztUK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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