SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '547e8835dcdc7033a1f2d08ef342b0fb72dfa04912781c9f1eeaaece8914f2ae' 
  AND token = 'h2gnyggrBz0HgmU98cVcxp0QZORmmYd+9ZmDCBegCPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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