SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '46476c32a3310060f7faec98495f68dfb147351c5aeabf97ae663d80c5bcbf65' 
  AND token = 'LkLZtRbOABDKf0MAOpE0/F7fD62YKxgj+mY7pUlNft8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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