SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0a0465020d3662ef7f58d30314d7906444181bdcb58f739465ee7ae7617d3d2' 
  AND token = 'IxPzIpASwyuwZXh6xY0ituqaqVCsUfMKV1nAx1l1YXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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