SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b1d797a0936abd2e78cb29b3d163fd0f59be543b560eee326c47ce1e1882967' 
  AND token = 'yktdkXsRb2lHYZEmLlUj51pcGQJvEZVYglyv6AhO9us=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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