SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f54b85ef99bab9b2bb5e3961ba26e5a7e64577afe64921c80e25fbba5aeb4c31' 
  AND token = 'MASYhpWGjzo9PwBrbx/RvhtEjTvqgrQEs/6vOMWhLz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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