SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9e1e38557c9f8fd568748d6e160b240e0dce01bd32f969ff605a832e20a549a6' 
  AND token = 'L1YgLMo25C1KHz0IjIrhaY53BMaVqZIoHu9z/VzTgpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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