SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '27b37e1784b168be97db4e857acf09e7dae895c658e0ed61ef2254cb9f7e3236' 
  AND token = 'zh8XvOCypCcCwmGkaSqOrSX9b79fZIcg+LETgCEqjag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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