SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '45b727d8358651a9e6a4417d5978086c9e4e7f3e325ef0f103a6f3c79ac46bb8' 
  AND token = 'yebQbkdz6XCO9h1JLOYxuB8urcvAh/JThg5YrZXeuVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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