SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8c0fd20f6f493f309226cac95cd5fb264ee504d80feca393bff75053c2e2eec9' 
  AND token = 'gDtYHpbQWij+eF48tX+gcrr3/fxu2zhF4xhJJ62BU+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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