SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9ac5ea250fa176dd0ed36172696a5a5fea616ae80727a1312cfe6b06f943e73e' 
  AND token = '3mktZ6DTFEQ73sLJyDMQl2JCDLACbY75JlqtL8qEQzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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