SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd3da245afd264e5ef9d1167c2423c7923b9ad42138984364f38cb4cf2a6f79c4' 
  AND token = 'SvuouvWgUlOBY31QOPQX7fSo2CsqmdjxU9AOwfN68jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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