SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '484404f7f8c66d23e8809c816c985cfc17679fbb64b55de13eec59fc8b345afe' 
  AND token = 'JVbaiHci1ZTzeoCcl7f5/6O+Qp/zLA10aMOrQTDgm00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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