SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b542521e11310be92cb64cc3b98af0614b65e90f12714072d9712093c6511636' 
  AND token = 'rOtHJGotxjzJB5f5Odc4QGQAibkAq/nzumsQoCB+7Bw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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