SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0c5141260dc9ebdc163cbbcc5ba7e3299fab993cc6aec5b75d5784935e46246d' 
  AND token = '9OiPMrRVPu2mcsJdsF3RtBoWMcs/HGUYoFbR1VbLxH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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