SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '828db945194c9a018f02483c2aa6c5a3fd64eec212e7a3c74e874a44b34fe4c5' 
  AND token = 'CzSUD0msCVkTPvL+D/B+0jbVwCZaLsi2T0x18Jsl9ig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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