SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4f08da5f47ce4812844c83e4fc389b31fce77c5c58280bc04cec4192358b30be' 
  AND token = '99NgXuRWWNJ3CA6j9LUR90F0UFi+1B+4knSrbrqCeJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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