SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66f6e12fa8c9131e5656fda1aa0ada80f1affc0ea6ffde3ca97d7ecd3364a99c' 
  AND token = 'LNZNRcYtFeA/Ql99egPVnk/OIu+iGsyw2A1WhkriA50=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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