SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '77ef7f48f4399c2b1c58147d2e3c05cda128003b0d45e03b76faeeaaf4c8fc6b' 
  AND token = 'Vs37ig/v/x9uwtP4gbKzVOYV/j968cuZlh4UUSH4rKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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