SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a038a41ea5234caed7eb99792f471970fa1c0f3a7f134b43f0579d220650b5aa' 
  AND token = '0qql3K/vNAbb6aSrs3N9smm+weRAFLYOb6g4FDmlp2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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