SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '15bc79ebede1dc866c13438022fe43825f010062de9bd21079a2075ce490a22b' 
  AND token = 'vT601Gq0w1lW4RCtk1fBmG3ExeqR3E10tt5pVq0kECM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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