SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ad5cbea34715e26e2405ce115646f8d03fd0f0d08ddae4bd90d79fed35ccfcf' 
  AND token = 'AnRMPBXoEn++22fkneZST6Srwa41Fk/tu99KoTG58Ew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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