SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5d7a78c1ceedbee3bea7175668f8d7dfb90744734bf9d8995106be8e959bb449' 
  AND token = 'B2lIs40nDSPJKOiHlrjC6rHcVxWJEZR9K/vw+IjeSHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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